Heart surgery

 
A mechanic was removing a cylinder head from the  motor of a Harley motorcycle when he spotted a well-known heart surgeon  in his shop.  The surgeon was there waiting for the service  manager to come take a look at his bike.

The mechanic shouted  across the garage, "Hey Doc can I ask you a  question?"   The surgeon, a bit  surprised, walked over to the mechanic working on the  motorcycle.  The  mechanic straightened up, wiped his hands on a rag and asked,  "So   Doc, look at this  engine. I open its   heart, take valves out, fix' them, put them  back in, and when I  finish, it works  just like new. So how come I get such a small salary and you get the really big bucks, when you and I are   doing   basically the same work?

The surgeon paused, smiled  and leaned over, and whispered to the mechanic..

" Try doing it with the engine  running . . ."